Fuel injection equipment of internal combustion engine comprise high pressure pump fluidly connected between a low pressure fuel system such as a transfer pump immersed in a fuel tank, and a high pressure system comprising a reservoir, such as a well-known common-rail, in which is stored pressurized fuel prior to be delivered and sprayed by fuel injectors into compression chambers of the engine.
A command unit receiving a plurality of information signals from the engine and the vehicle generates command signals for adjusting operational parameters of the injection equipment to the engine demand.
For instance, to match the engine demand for speed, acceleration or deceleration of the vehicle, the quantity and pressure of fuel to be sprayed is computed by the command unit which in turn generates orders commanding each component of the injection equipment, transfer pump, high pressure pump, injectors, an operational behavior adapted to said engine demand.
In gasoline engines, said quantity and volume of pressurized fuel is regulated by the command unit via electrical means such as an electrical pump or an electrical spill valve. In addition to the cost incurred because of said electrical actuators, the acoustic noise generated by the motions commanded has become a major issue.